Method and apparatus for TIG welding
US4947021A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 30, 1989 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | May 30, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K9/1006
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for TIG welding by passing an alternating current between a non-consumable electrode and a workpiece to form an arc, which apparatus comprises a single reactor with first and second coil portions and a common core, passing a direct current from a direct current power supply through the first coil portion of the reactor and in a negative direction from the workpiece to the electrode for creating a heating cycle, switchably disconnecting the direct current power supply from the circuit and immediately connecting the second coil portion of the reactor in a positive direction across the electrode and workpiece for creating a short cleaning cycle for cleaning the workpiece preparatory to the next heating cycle. These heating and cleaning cycles are continued to create a TIG welding process. During the negative current flow, energy and/or current to the arc is controlled by pulsing a FET switch with a pulse width modulated device adjusted by an error signal created by comparing the sensed arc current and a reference signal or set point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.